Thread tensioning means



K. SCHWABE THREAD. TENSIONING MEANS Filed June 22. 1956 INVENTOR.

KURT SCHWA BE A lforneys United States PatentOfiice THREAD TENSIONING MEANS Kurt Schwabe, Le Locle, Switzerland, assignor to Tissomat A.G., Glarus, Switzerland Filed June 22, 1956, Ser. No. 593,249

Claims priority, application Switzerland June 24, 1955 3 Claims. or. 139-247 The invention relates to means for tensioning the threads of the weft bobbins provided in the cells or compartments of the bobbin magazines in automatic looms.

It is known to use automatic multiple box looms which are provided with a bobbin magazine consisting of several cells or compartments which are provided side by side to receive weft bobbins of difierent colour. The free ends of the weft threads of the weft bobbins in the different compartments of the bobbin magazine are attached to an attachment member and must be kept taut to ensure that bobbin exchange proceeds smoothly. When a bobbin from one of the cells of the bobbin magazine is knocked or projected by means of a hammer into a shuttle the weft bobbin of which is to be replaced, the weft bobbins provided in this particular compartment will move downwards so that the tension of the weft threads of these bobbins is altered, and it in the course of several bobbin exchanges, a weft bobbin is moved from the up permost part to the lowermost part of a compartment of the bobbin magazine, the tension of its initially tensioned weft thread is reduced and the thread becomes slack, thus causing trouble with'the bobbin exchange, "and particularly with the threading of the shuttle. 1 It is the object Olf the present invention to provide means whereby these disadvantages may be removed or appreciably reduced.

The invention provides a mechanism for tcnsioning the threads of the Weft bobbins provided in the compartments of the 'Ibobbin magazine in automatic looms, in which the bobbin magazine carries a support which is formed with guide means for each individual compartment of the bobbin magazine, a hook being displaceably guided in the guide means to engage the collected ends of the Weft threads of all the weft bobbins disposed in the respective compartment of the bobbin magazine, the ends of these weft threads being attached to an attachment member which is also provided on the support so that the ends of these Weft threads are kept taut by the action of a force exerted on the hook.

One construction according to the invention is diagrammatically illustrated by way of example in the accompanying drawings, in which:

Figure 1 is a side elevation of a device for tensioning the threads of the weft bobbins provided in the compartmentsof the bobbin magazine of an automatic multiple box loom, and

Figure 2 is a plan of the device a part being omitted .to facilitate understanding of the drawings.

In the construction illustrated in the drawings, it is :assumed that the bobbin magazine of the automatic -multiple box loom comprises four cells or compartments .a, b, c, and d which are provided side by side. 1 denotes one wall of the bobbin magazine, which is only shown ."by way of indication and not in detail. The wall 1 is formed with a bearing member or boss 2 in which a "bolt 3 is securely inserted. One internally threaded end aof a tube 4 is in threaded engagement with the bolt 3, .and the other internally threaded end of the tube 4 is in Patented Oct. 1 l I 1 960 threaded engagement with a bolt 5 provided with a hexagon head. A spherical supporting member 6 the upper side of which carries a bifurcated member 6', and the underside of which is in threaded engagement with a vertical supporting rod 7, is mounted on the bolt 5. A supporting member 9 the outline of which in'plan is that of the sector of a circle and which is secured in position by means of a clamping screw 8, is mounted on the supporting rod 7. The supporting member 9 is formed on its periphery with four bearing members'or eyes 10 in each of which the upper end of a tubular casing 11 is securely mounted, each tubular casing 11 being closed at the bottom and having its upper end rounded ofi and flared at the level of the upper side of the supporting member 9. In each tubular casing 11 there is displaceably guided a cylindrical weight 12 the top end of which is in coaxial, threaded engagement with a rod 13 which is formed with a hook. A bolt 14 provided with a handle and adapted to slide in a longitudinal slot 15 of the tubular casing 11 is screwed laterally into each of the weights 12. A locking member or slot 16 for the bolt 14 is provided at the upper end of each longitudinal slot 15. Four upwardly extending guide rods 17 are secure- 1y mounted in parallel relation in the supporting member 9 between the supporting rod 7 and the tubular casing 11. Each bearing member or eye 10 is provided with a jaw 18 which projects laterally outwards, each jaw 18 being formed with a boring in which the threaded shank of a bolt 19, which is held in position on the jaw 18 by a nut 20 with which it is in threaded engagement, is inserted. Each bolt 19 is secured to one end of a spiral spring 21, while the other end ofthe spiral spring 21 is secured to a bolt 22 on which a lever 23 is mounted. The spiral spr'mg 21, the turns of which lie close-together, so as to contact each other, can be expanded by the lever 23. On the supporting member 9 at a position above each spiral spring 21, there is provided a slotted guide member 24 which forms a guide face extending from the rounded 01f, flared end of the tubular casing 11 to the spiral spring 21. On each side of the supporting memher 9 and securely mounted therein between the two outer bearing members or eyes 10 is a downwardly extending rod 25 carrying a head 26 which functions as the means to which the Weft threads are attached.

The weft bobbins, arranged according to colour, are inserted in the compartments a, b, c and d of the bobbin magazine in which they lie one above the other. The ends of the weft threads of all of the weft bobbins are first laid collectively over the bifurcated member 6' so as to ensure that they cannot become entangled anywhere. The ends of the weft threads of all the weft bobbins disposed in the compartment a of the bobbin magazine, are then collected, laid around the outermost guide rod 17 disposed on the same side as the compartment a and threaded into the hook of the rod 13 of the weight 12 which is provided in the tubular casing 11 disposed radially outwards from this guide rod 17, the Weight 12 being locked in its uppermost position, in which position the rod 13 with its hook projects from the supporting member 9. The ends of the individual casing 11, the weight 12 being thus suspended, as by I means of the hook on the rod 13, from the weft threads of the weft bobbin provided in the compartment a of the bobbin magazine, which weft threads are thus maintained taut. The ends of the weft threads of the weft "2,955,620 A A f 4 l bobbins provided in the other compartments b, c and d of the bobbin magazine are dealt with in the same mannet in that a weight 12 is suspended from the collected thread ends of the weft bobbins of each individual compartment to keep these weft thread ends taut. If necessary, the weights 12 may be weighted with an additional weight 27. When a weft bobbin is taken from one of the compartments of the bobbin magazine by the bobbin exchanging device of the multiple box loom, the ends of the weft threads of the weft bobbins which remain in this compartment of the bobbin magazine and which move downwards, cannot become sl-ack as they are always re-tensioned by the weight 12 suspended therefrom.

The outline in plan of the supporting member 9 is provided to be that of the sector of a circle as it is thus made possible to provide the tubular casing 11 in a small space.

Instead of being loaded with the Weight 12, the rod '13 carrying the book may also be guided in guide means and subjected to the action of a spring so that the weft threads threaded into or through the hook of the rod 13 are kept tensioned by the force of the spring, which force is advantageously adjustable.

I claim:

1. Apparatus for tensioning the threads of weft bobbins contained in a compartment of the bobbin magazine; a helical spring for releasably clamping the ends of the weft threads, one end of the helical spring being fixed, and the helical spring having some at least of its coils closely adjacent to each other whereby to grip the threads; means for expanding the helical spring to separate the coils, said means having means attached to the other end of the helical spring operable for rotating the said other end of the helical spring relative to the said one end thereof; a member for slidably engaging the threads at a position between the helical spring and the bobbin magazine; and means applying a force to the engaging member in a direction to maintain the weft threads under tension.

2. Apparatus for tensioning the threads of weft bobbins contained in the compartments of the bobbin magazine of an automatic loom, comprising, in combination, an arcuate supporting member secured to the bobbin magazine; retaining members arcuately spaced about the supporting member for retaining the ends of the threads of the bobbins, each of said retaining members comprising a helical spring having at least some of its coils closely adjacent to each other, a pair of jaws between which each of the helical springs is mounted, means securing one end of each helical spring to one of the pertaining jaws and a lever secured to the other end of each helical spring and rotatably mounted on the other of the pertaining jaws whereby rotation of the lever in one direction about its axis serves to separate the coils of the helical spring; a plurality of means also arcuately spaced about the supporting member for slidably engaging the threads at positions between the retaining members and the compartments of the bobbin magazine, one of said engaging means being provided for each of said compartments; a plurality of guide means .for the said engaging means, one of said guide means being provided for each of said engaging means; and means applying a force to the engaging means in a direction to maintain the threads under tension.

3. Apparatus according to claim 2, in which each said guide means is a tubular casing suspended from said supporting member and provided with a longitudinal slot, and each said engaging means being provided with a lateral member extending through the longitudinal slot of the pertaining guide means.

References Cited in the file of this patent UNITED STATES PATENTS 1,760,982 Gordon June 3, 1930 1,786,671 Morrell Dec. 30, 1930 1,793,170 Gerber Feb. 17, 1931 1,817,136 Gordon Aug. 4, 1931 1,826,312 Gordon Oct. 6, 1931 

